Risk and risk assessment for breast cancer: Molecular and clinical aspects

Breast cancer risk assessment using the Gail model: a Turkish study

PURPOSE

This study was conducted to determine risk of developing of breast cancer among Turkish women.

MATERIALS AND METHODS

Using a descriptive and cross-sectional approach, data were collected from 231 women. Breast cancer risk was calculated using the National Cancer Institute's on-line verson of called as the Breast Cancer Risk Assessment Tool or the Gail Risk Assesment Tool.

RESULTS

The average age of women was 45.0±8.06 years. It was revealed that 6.1% of participants reported having first degree relatives who had had breast cancer, with only four women having more than one first-degree relative affected (1.7%). The mean five-year breast cancer risk for all women was 0.88±0.91%, and 7.4% of women had a five-year breast cancer risk >1.66% in this study. Mean lifetime breast cancer risk up to age 90 years was 9.3±5.2%.

CONCLUSIONS

The breast cancer risk assessment tool can help in the clinical management of patient seeking advice concerning screening and prevention. Healthcare providers in Turkey can use this approach to estimate an individual's probability of developing breast cancer.

Insulin-like growth factor and epidermal growth factor signaling in breast cancer cell growth: focus on endocrine resistant disease

Breast cancer is the most common type of cancer for women worldwide with a lifetime risk amounting to a staggering total of 10%. It is well established that the endogenous synthesis of insulin-like growth factor (IGF) and epidermal growth factor (EGF) polypeptide growth factors are closely correlated to malignant transformation and all the steps of the breast cancer metastatic cascade. Numerous studies have demonstrated that both estrogens and growth factors stimulate the proliferation of steroid-dependent tumor cells, and that the interaction between these signaling pathways occurs at several levels. Importantly, the majority of breast cancer cases are estrogen receptor- (ER-) positive which have a more favorable prognosis and pattern of recurrence with endocrine therapy being the backbone of treatment. Unfortunately, the majority of patients progress to endocrine therapy resistant disease (acquired resistance) whereas a proportion of patients may fail to respond to initial therapy (de novo resistance). The IGF-I and EGF downstream signaling pathways are closely involved in the process of progression to therapy resistant disease. Modifications in the bioavailability of these growth factors contribute critically to disease progression. In the present review therefore, we will discuss in depth how IGF and EGF signaling participate in breast cancer pathogenesis and progression to endocrine resistant disease.

Validation of three BRCA1/2 mutation-carrier probability models Myriad, BRCAPRO and BOADICEA in a population-based series of 183 German families

Many studies have evaluated the performance of risk assessment models for BRCA1/2 mutation carrier probabilities in different populations, but to our knowledge very few studies have been conducted in the German population so far. In the recent study, we validated the performance of three risk calculation models by names BRCAPRO, Myriad and BOADICEA in 183 German families who had undergone molecular testing of mutations in BRCA1 and BRCA2 with an indication based on clinical criteria regarding their family history of cancer. The sensitivity and specificity at the conventional threshold of 10% as well as for a threshold of 20% were evaluated. The ability to discriminate between carriers and non-carriers was judged by the area under the receiver operating characteristics curve. We further focused on the performance characteristic of these models in patients carrying large genomic rearrangements as a subtype of mutations which is currently gaining increasing importance. BRCAPRO and BOADICEA performed almost equally well in our patient population, but we found a lack of agreement to Myriad. The results obtained from this study were consistent with previously published results from other population and racial/ethnic groups. We suggest using model specific decision thresholds instead of the recommended universal value of 10%. We further suggest integrating the CaGene5 software package, which includes BRCAPRO and Myriad, in the genetic counselling of German families with suspected inherited breast and ovarian cancer because of the good performance of BRCAPRO and the substantial ease of use of this software.

Risk of developing breast cancer by utilizing Gail model

The Gail model has been widely used to quantify an individual woman's risk of developing breast cancer by using important clinical parameters, usually for clinical counselling purposes or to determine eligibility for mammography and genetic tests. The aim of the present study was to estimate the five-year and lifetime breast cancer risk among women in Rasht, Iran. In this cross-sectional study, 314 women were evaluated at Alzahra Women Hospital in 2007. Participants were ≥35 years of age without a history of breast cancer. Risk estimation was performed using the computerized Gail model. A five-year risk >1.66% was considered high-risk; 5.1% of women were high-risk. The mean five-year breast cancer risk was 0.8% (SD±1). Mean breast cancer risk up to the age of 90 years (lifetime risk) was 9.0% (SD±3.9%); 16.2% of the participants had a five-year risk higher than the average woman of the same age, and 18.2% had the same risk. Also for the lifetime risk, 11.1% of the women had higher risk and 1.6% had the same risk as the average woman. Routine use of the Gail model is recommended for identifying women at high average risk for increasing the survival of women from breast cancer.

Using zebrafish to learn statistical analysis and Mendelian genetics

This project was developed to promote understanding of how mathematics and statistical analysis are used as tools in genetic research. It gives students the opportunity to carry out hypothesis-driven experiments in the classroom: students generate hypotheses about Mendelian and non-Mendelian inheritance patterns, gather raw data, and test their hypotheses using chi-square statistical analysis. In the first protocol, students are challenged to analyze inheritance patterns using GloFish, brightly colored, commercially available, transgenic zebrafish that express Green, Yellow, or Red Fluorescent Protein throughout their muscles. In the second protocol, students learn about genetic screens, microscopy, and developmental biology by analyzing the inheritance patterns of mutations that cause developmental defects. The difficulty of the experiments can be adapted for middle school to upper level undergraduate students. Since the GloFish experiments use only fish and materials that can be purchased from pet stores, they should be accessible to many schools. For each protocol, we provide detailed instructions, ideas for how the experiments fit into an undergraduate curriculum, raw data, and example analyses. Our plan is to have these protocols form the basis of a growing and adaptable educational tool available on the Zebrafish in the Classroom Web site.

Risk assessment in familial breast cancer

Women with a history of breast cancer are common at centers for cancer genetic risk all over Europe. Given limited health care resources, managing this demand, while achieving good value for money coming from health services, is generally a major challenge. This paper recapitulates and summarizes the available methods of the risk assessment of familial breast cancer. After a systematic review of the literature Gail-model, Claus-model and BOADICEA-model were selected, as well as softwares (LINKAGE software; MENDEL v3.3 software) available in the application of these algorhythms are also summarized. Comparisons were made between the models concerning their advantages and disadvantages. The really reliable methods of risk estimation of familial breast cancer are always based on the analysis of the pedigree structure and allow the estimation of the patient’s probability of carrying a susceptibility gene under a particular genetic model, given her family history. For this method the knowledge of BRCA mutation status is absolutely indispensable. The methods of BRCA mutation analysis as well as the main characteristics of the occurrence of BRCA mutation carrier condition are discussed in details. Orv. Hetil., 2011, 152, 758–762.

Preventive oncology in the postmenopausal woman

Breast cancer and endometrial cancer are the most common gynecologic malignancies of the postmenopausal period. As preventive medicine becomes the focus of interest, preventive oncology with special regard to these diseases will undoubtedly become a substantial part of the practicing oncologist's field of duties. The aim of this review is to summarize recommendations dealing with the risk assessment and prevention of breast and endometrial cancer. Obesity, the level of exercise and dietary factors are associated with breast cancer. The selective estrogen receptor modulators tamoxifen and raloxifen have both been shown to decrease the risk to the same extent. Patients at particularly high risk are being detected through the use of the Gail model, a well-known statistical model of risk. Other factors, such as breast density, the serum level of endogenous estrogen and the presence of single nucleotide polymorphisms, have to be taken into consideration.